To clean or not to clean? This is one of the most frequently asked questions by conservators who deal with artworks made of softened plastics. The essence of this conservation puzzle is the process that takes place at the molecular level. Let’s imagine a space loosely filled with long polymer chains, which are the basic building blocks of every plastic. Much smaller plasticiser molecules penetrate between the tangled polymer chains, pushing them apart and softening the material. Sounds like the perfect way to adapt the material’s properties to the artist’s vision? Unfortunately, the size of the plasticiser molecules and their limited miscibility with polymer have consequences: efflorescence and appearance of a liquid with a viscosity resembling honey. These signs of chemical degradation of artworks raise doubts among conservators.
Wouldn’t cleaning the surface of Tadeusz Kantor’s mannequins contribute to their even faster deterioration? This issue requires looking at two primary processes related to the migration of plasticiser molecules. Initially, these molecules move from inside the object towards its surface, from which they then evaporate. The rate of these individual processes determines whether a conservation procedure involving the removal of efflorescence is safe for a given object. If the plasticizer evaporates much slower than it penetrates the material, its removal will not have a negative effect on the condition of the object.
While waiting for reviews of our publications, we decided to face the inevitable and present the results obtained so far in the picturesque surroundings of the Swiss Alps at the conference Scientific Methods in Cultural Heritage Research organized by Gordon Research Conferences. However, we aim to answer questions raised by practitioners and to transfer scientific knowledge to the museum community. Owing to cooperation with The Centre for the Documentation of the Art of Tadeusz Kantor Cricoteka, we had the opportunity to share our current findings with its employees and discuss potential risks to mannequins from the Cricoteka collection, for which we are enormously grateful!
The PVCare project ‘Preventive conservation strategies for poly(vinyl chloride) objects’ is financed by the National Science Center Poland (2020/39/I/HS2/00911) and the Slovenian Research Agency ARIS (N1-0241) as part of the OPUS-LAP 20 programme.